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framer-motion

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A simple and powerful JavaScript animation library

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'use strict'; Object.defineProperty(exports, '__esModule', { value: true }); var react = require('react'); var motionDom = require('motion-dom'); var motionUtils = require('motion-utils'); /** * Creates a constant value over the lifecycle of a component. * * Even if `useMemo` is provided an empty array as its final argument, it doesn't offer * a guarantee that it won't re-run for performance reasons later on. By using `useConstant` * you can ensure that initialisers don't execute twice or more. */ function useConstant(init) { const ref = react.useRef(null); if (ref.current === null) { ref.current = init(); } return ref.current; } function useUnmountEffect(callback) { return react.useEffect(() => () => callback(), []); } function animateElements(elementOrSelector, keyframes, options, scope) { const elements = motionDom.resolveElements(elementOrSelector, scope); const numElements = elements.length; motionUtils.invariant(Boolean(numElements), "No valid element provided."); /** * WAAPI doesn't support interrupting animations. * * Therefore, starting animations requires a three-step process: * 1. Stop existing animations (write styles to DOM) * 2. Resolve keyframes (read styles from DOM) * 3. Create new animations (write styles to DOM) * * The hybrid `animate()` function uses AsyncAnimation to resolve * keyframes before creating new animations, which removes style * thrashing. Here, we have much stricter filesize constraints. * Therefore we do this in a synchronous way that ensures that * at least within `animate()` calls there is no style thrashing. * * In the motion-native-animate-mini-interrupt benchmark this * was 80% faster than a single loop. */ const animationDefinitions = []; /** * Step 1: Build options and stop existing animations (write) */ for (let i = 0; i < numElements; i++) { const element = elements[i]; const elementTransition = { ...options }; /** * Resolve stagger function if provided. */ if (typeof elementTransition.delay === "function") { elementTransition.delay = elementTransition.delay(i, numElements); } for (const valueName in keyframes) { let valueKeyframes = keyframes[valueName]; if (!Array.isArray(valueKeyframes)) { valueKeyframes = [valueKeyframes]; } const valueOptions = { ...motionDom.getValueTransition(elementTransition, valueName), }; valueOptions.duration && (valueOptions.duration = motionUtils.secondsToMilliseconds(valueOptions.duration)); valueOptions.delay && (valueOptions.delay = motionUtils.secondsToMilliseconds(valueOptions.delay)); /** * If there's an existing animation playing on this element then stop it * before creating a new one. */ const map = motionDom.getAnimationMap(element); const key = motionDom.animationMapKey(valueName, valueOptions.pseudoElement || ""); const currentAnimation = map.get(key); currentAnimation && currentAnimation.stop(); animationDefinitions.push({ map, key, unresolvedKeyframes: valueKeyframes, options: { ...valueOptions, element, name: valueName, allowFlatten: !elementTransition.type && !elementTransition.ease, }, }); } } /** * Step 2: Resolve keyframes (read) */ for (let i = 0; i < animationDefinitions.length; i++) { const { unresolvedKeyframes, options: animationOptions } = animationDefinitions[i]; const { element, name, pseudoElement } = animationOptions; if (!pseudoElement && unresolvedKeyframes[0] === null) { unresolvedKeyframes[0] = motionDom.getComputedStyle(element, name); } motionDom.fillWildcards(unresolvedKeyframes); motionDom.applyPxDefaults(unresolvedKeyframes, name); /** * If we only have one keyframe, explicitly read the initial keyframe * from the computed style. This is to ensure consistency with WAAPI behaviour * for restarting animations, for instance .play() after finish, when it * has one vs two keyframes. */ if (!pseudoElement && unresolvedKeyframes.length < 2) { unresolvedKeyframes.unshift(motionDom.getComputedStyle(element, name)); } animationOptions.keyframes = unresolvedKeyframes; } /** * Step 3: Create new animations (write) */ const animations = []; for (let i = 0; i < animationDefinitions.length; i++) { const { map, key, options: animationOptions } = animationDefinitions[i]; const animation = new motionDom.NativeAnimation(animationOptions); map.set(key, animation); animation.finished.finally(() => map.delete(key)); animations.push(animation); } return animations; } const createScopedWaapiAnimate = (scope) => { function scopedAnimate(elementOrSelector, keyframes, options) { return new motionDom.GroupAnimationWithThen(animateElements(elementOrSelector, keyframes, options, scope)); } return scopedAnimate; }; function useAnimateMini() { const scope = useConstant(() => ({ current: null, // Will be hydrated by React animations: [], })); const animate = useConstant(() => createScopedWaapiAnimate(scope)); useUnmountEffect(() => { scope.animations.forEach((animation) => animation.stop()); }); return [scope, animate]; } exports.useAnimate = useAnimateMini;